Abstract
Purpose :
In central serous chorioretinopathy (CSC), filling delay and dilated choroidal vessels represent indocyanine green fluorescein angiography (ICGA). To investigate the three-dimensional structure of the choroidal vasculature corresponding to ICGA findings, we analyzed three-dimensional structural OCT (OCT-S) and OCT angiography (OCT-A) superimposing ICGA images.
Methods :
Subjects were 30 CSC patients, 30 eyes of 30 patients, age 55 ± 12 (mean ± standard deviation) years, female: male = 9:21. ICGA identified filling delay regions from mid-phase images using HRA2. OCT images were taken in a 6x6 mm area using Elite 9000, and an en-face projection image was generated using Image J. The mid-phase ICGA image is transformed and aligned to OCT-S en-face projection image based on the retinal blood vessels by moving least squares methods. ICGA, OCT-S, and OCT-A were observed using 3D slicer, which allow us to identify the x-y-z position and extension of the choroidal vessel.
Results :
Several narrow and weak fluorescent vessels in ICGA were identified within the delayed filling area. These vessels connected to the dilated veins running near the filing delay when the vessels were traced three-dimensionally in 26/30 (87%) eyes and showed dilatation in OCT-S in 19 of 26 (63%) eyes. Some dilated vessels crossed over the vessel penetrating from the lamina fusca, which was thought to be a branch of the ciliary artery. Low-intensity areas connecting to flow void in the choriocapillaris appeared around dilated vessels in filling delay in 23/26 (88%) eyes.
Conclusions :
Some vessels running in delayed filling areas were identified as choroidal veins. The vessels showed the following characteristics: weak fluorescence in ICGA, dilation in OCT-S compared to the appearance of the vessels in ICGA, and low-intensity area connected to flow void in the choriocapillaris in OCT-A. The results imply congestion in the vein. Regionally increasing venous pressure may increase the pressure in the choriocapillaris and cause filling delay. Blood overflowing from the delayed filling area may be another cause of venous overload in the venous system of the choroid in CSC.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.